You have probably heard the term "cat" or "cat back" before when talking about exhaust systems and parts. These abbreviations for "catalytic converter" are often used among mechanics and tuners for sake of brevity. Nevertheless, few people know much about the importance of the catalytic converters installed in their vehicles and how to improve their efficiency or prevent premature failure, outside of this small auto-centric circle.
Catalytic converters are often in the news only when a rash of thefts affects a community. The valuable platinum group elements found in catalytic converters make them prime targets for opportunistic thieves who can cross state lines and sell them for profit to scrapyards. Over $3 billion in recycled precious metals from catalytic converters is reclaimed annually. The cost of the original catalytic converters and the precious metal substrate was one of the early hurdles in mandating their universal usage in automobiles. Learn more about catalytic converters by reading onward.
What is a Catalytic Converter?
A catalytic converter is an emissions control component that is found in the exhaust systems of most modern combustion engines that run on gasoline. This includes planes, buses, cars, trucks, motorcycles, and trains. It is a type of passive regeneration system catalyst that alters the molecular structure of nitrous oxides (NOx), hydrocarbons (HC), and poisonous carbon monoxide (CO). "Passive regeneration" means that there is no electromechanically actuated cycle to burn off the toxins accumulated. As long as the catalytic converter reaches normal operating temperatures of 500 to 600 degrees Fahrenheit, it will function as intended without any additional maintenance required. The only time that problems may occur is if the catalyst overheats, the engine experiences running problems, or the sensors which measure and regulate the amount of oxygen in the exhaust malfunction.
Why Do Cars Have Catalytic Converters Installed?
Catalytic converters started to appear on vehicles in 1975 in response to studies by the EPA and strategies on how to improve US air quality. These early catalytic converters were very expensive for car manufacturers to standardize in their autos and prone to premature failure from overheating. Today, automobiles and just about anything else that runs on gasoline requires a catalytic converter that is working properly to pass stringent emissions tests. These catalytic converters are working on saving the environment from deadly carbon monoxide, nitrous oxides, and hydrocarbon soot. The greenhouse gases produced by combustion engines are associated with city smog, global warming, rising ocean levels, environmental destruction, and the increase in turbulent weather patterns. For a device that only costs a few hundred dollars to manufacture, the benefits to humanity are extraordinary.
How Does a Catalytic Converter Work?
A catalytic converter works in two similar processes to clean up the toxicity of combustion engine exhaust fumes. The catalytic converter is connected in-line with the exhaust system, but far enough away from the engine to prevent overheating. The honeycomb version features two separate precious metal substrate catalysts that react with the exhaust gases and separate the molecules into safer byproducts by simply passing over the materials at high temperatures. In the first honeycomb chamber reduction catalyst, Platinum (Pt) and Rhodium (Rh) bond to the Nitrogen (N) atom of dangerous nitrous oxide (NOx) gases. In the second honeycomb chamber reduction catalyst, a mixture of Platinum (Pt) and Palladium (Pd) break up the hydrocarbons and deadly carbon monoxide gas. The oxygen sensors mounted in the exhaust system help to regulate engine combustion processes by ensuring that an ideal fuel to air mixture is achieved (14.7 pounds of oxygen per 1 pound of fuel).